Queston #6897Note

Inability to abduct (deltoid), lateral rotation of arm at the shoulder (posterior deltoid, infraspinatus, and teres minor), flexion (biceps), supination of the forearm (brachioradialis), and sensory loss over the lower deltoid
– think upper roots of brachial plexus injury
– nerves most commonly affected = suprascapular nerve, musculocutaneous nerve, and axillary nerve 

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Lower brachial plexus injury => “Klumpke’s palsy”
– due to T1 and C8 injury => intrinsic hand muscle paralysis (T1) and paralysis of the ulnar flexors at the wrist and fingers (C8)
– hyperextension of the metacarpophalangeal joints and flexion at the interphalangeal joints